Which California peninsula includes San Francisco and extends south between San Francisco Bay and the Pacific Ocean?

The San Francisco Peninsula is the California peninsula that includes San Francisco and extends south between San Francisco Bay and the Pacific Ocean.

The peninsula’s northern tip is occupied by the city and county of San Francisco. South of the city, the landform continues through San Mateo County toward the Santa Cruz Mountains and the communities of Silicon Valley’s western side. San Francisco Bay borders its eastern side, while the Pacific Ocean borders its western side.

The name can cause confusion because “the Peninsula” may refer either to the physical landform or, in local usage, especially to San Mateo County and nearby communities south of San Francisco. The broader geographic peninsula also includes San Francisco itself.

The Golden Gate forms the peninsula’s northern entrance, separating it from Marin County to the north. The Santa Cruz Mountains run along much of its spine, creating a strong divide between bay-side and ocean-side landscapes.